package cn.tedu.sp06.fb;

import cn.tedu.sp01.util.JsonResult;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

@Component
@Slf4j
public class ItemFB implements FallbackProvider {
    //设置针对按个后台服务进行降级
    @Override
    public String getRoute() {
        return "item-service";
    }
    //向客户端发回的降级响应
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();
            }

            @Override
            public void close() {
            //用来关闭下面的输入流;
            //BATS虚拟机中读取byte[]数组的流对象
            //不占用底层系统资源
            }

            @Override
            public InputStream getBody() throws IOException {
                String json = JsonResult.err().code(500).msg("后台服务出错,请稍后重试").toString();
                //用BAIS封装json结果
                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders h = new HttpHeaders();
                h.add("Content-type", "application/json;charset=UTF-8");
                return h;
            }
        };
    }
}
